事件定义：
  /// <summary>
  /// 自定义事件委托
  /// </summary>
  public delegate void ExpertListCommandEventHandler(object sender, Professor.UserControls.ExpertListCommandEventArgs e);/// <summary>
  /// 定义事件
  /// </summary>
  public event ExpertListCommandEventHandler Command;/// <summary>
  /// 引发事件的方法
  /// </summary>
  public void RaiseCommandEvent(Professor.UserControls.ExpertListCommandEventArgs e)
  {
   this.Command(this, e);
  }
事件特性（参数）类：必须继承自EventArgs. 可包含多种类型数据.
 public class CommandEventArgs: System.EventArgs
 {
  private string commandName;
  /// <summary>
  /// 命令名称.
  /// </summary>
  public string CommandName
  {
   get
   {
    return this.commandName;
   }
   set
   {
    this.commandName = value;
   }
  }private int id;
  /// <summary>
  /// 操作对象: 被操作的专家ID数列
  /// </summary>
  public int Id
  {
   get
   {
    return this.id;
   }
   set
   {
    this.id = value;
   }
  }
 }